Drafting apparatus

ABSTRACT

An apparatus to stop the supply of roving to a drafting system when an end breaks to prevent lap damage to the drafting system by physically rotating a stop member into the path of flow of the roving supply.

United States Patent Inventors Grady H. Sanders;

Robert M. Ingham, Jr., both of Spartanburg, S.C.

Appl. No. 838,212

Filed July 1, 1969 Patented Sept. 14, 1971 Assignee Deering MillikanResearch Corporation Spartanburg, S.C.

DRAFTING APPARATUS 5 Claims, 5 Drawing Figs.

19/255 Int. ("I D0lh 13/18 Field of Search 19/126,

References Cited UNITED STATES PATENTS Tabor Tolman et a1. RhoadesCampbell Holmes Henry Walsh Oswald Primary Examiner-Dorsey NewtonAtlomeys-Norman C. Armitage and H. William Petry l9/.26 57/84 57/8757/87 l9/.26 l9/.26 19/253 X 19/283 ABSTRACT: An apparatus to stop thesupply of roving to a drafting system when an end breaks to prevent lapdamage to the drafting system by physically rotating a stop member intothe path of flow of the roving supply.

PATENTED SEP] 4 I97! SHEET 1 OF 2 INVENTORS SA N D E R S M.|NGHAM,JR.

ATTORNEY PATENIEU SEPI4I97I I SL604; 195

SHEET 2 0F 2 40 A 1' 2m 54 so a I l 24 g 1 80 E 74 7o 84 I 9 7 84 72INVENTORS GRADY H. SANDERS ROBERT M.INGHAM,JR. BY

ATTORNEY DRAFTING APPARATUS This invention relates generally to draftingsystems for spinning frames and in particular in the prevention of lapdamage to a drafting system when an undetected yearn break occursbetween the ring rail and the front rolls of the drafting system.

When drafting roving or sliver prior to spinning into yarn very often abreak will occur between the rear drafting rolls and the ring andtraveler of the spinning frame. Normally, the break will occur betweenthe front drafting rolls-and the ring and traveler of the spinningframe. When this condition happens the roving or sliver being suppliedto the drafting system will continue to be supplied to the front rollscausing the roving or sliver to wrap around the front rolls and thenpile up between the front and middle drafting rolls. This pileup offibers between the rolls can cause the aprons to freeze and be torn upby the rotating rolls. This condition is very severe on the lowerdrafting apron since the middle lower drafting roll is normally knurledwhich chews up the inside of the apron. If the condition occurs veryoften it causes a lot of inconvenience since only a limited number ofspare aprons are available on the lower rolls and when these areexhausted it is necessary to use spliced aprons which are ineflicient inoperation, thereby lowering the spinning frame efficiency and the yarnquality. Further, if there is a large buildup of fibers between therolls, there will be a tendency for the drafting cradle to be broken andthereby not only require replacing of the cradle but also resulting inthe destruction of both the drafting aprons.

It is therefore an object of the invention to provide a method andapparatus to prevent lap damage to a drafting system.

Another object of the invention is to provide a lap damage the roving orsliver being supplied to a drafting system when a break occurs in thefiber being drafted and/or spun.

A still further object of the invention is to provide a roving stopsystem which is sensitive to a lap up on either the top or bottom frontroll of a drafting system.

Other objects and advantages of the invention will become readilyapparent as the specification proceeds to describe the invention withreference to the accompanying drawings, in which:

FIG. 1 is a schematic view of a drafting system in normal position andincorporating the herein disclosed invention;

FIG. 2 is a view similar to FIG. 1 illustrating the condition of thedrafting system when an end break occurs;

FIG. 3 is a bottom view of two drafting positions showing normaloperating positions of the lap-up detector;

FIG. 4 is a blown-up perspective view of the new and improved rovingstop incorporated in the drafting system of FIGS. I3;and '7 FIG. 5 is ablown-up view of the new and improved cradle employed in the draftingsystems of FIGS. l-3.

Looking now to the drawings, FIG. 1 showsthe improved drafting system inconventional operation with a roving or sliver of staple fibers passingthrough a condenser, supported by elongated bar 13, into the nip ofupper and lower rear drafting rolls l4 and 16, middle drafting rolls l8and 20, front drafting rolls 22 and 24 to a ring and traveler (notshown) to form yarn Y by placing twist therein between the ring andtraveler and the nip of front drafting rolls 22 and 24. Conventionally,top drafting rolls l4 and 22 are rubber covered rolls while intermediatetop drafting roll 18 is knurled. Bottom front and rear drafting rolls 24and 16 are fluted rolls while the middle bottom roll is knurled.

Inasmuch as the major amount of drafting is conventionally accomplishedin the zone between the middle rolls 18, 20 and the front rolls 22, 24from which the fibers proceed and are either twisted into yarn ordrafted further, and since the running mass of fibers is also broughtinto a minimum size in the zone between the middle and front pair ofrollsfit is most preventer for a drafting systemwhich will stop thedelivery of desirable that the fibers be controlled as closely aspossible and to this purpose a double-apron system, consisting of upperendless apron 26 and lower endless apron 28, is used. In a mannerexemplified in the art, e.g., US. Pat. No. 3,386,]36, upper and lowerapron clearing and roll engaging members 30 and 31 connected to cradle32 are supported within the aprons 26 and 28 and at one end have aconcave surface 34 engaging the rolls to clean the peripheral surfacethereof and at the other end an apron reversing nose portion. Cradle 32,which has two upstanding wall members 38, has a conventional rovingshelf secured therebetween to guide the roving into the nip of thedrafting rolls and between the middle and back rolls, thereby preventinga lap up due to improper feed of the roving into the drafting system.

Looking at FIG. 5, the cradle 32 is shown in detail. Cradle 32preferably is made from a material which is readily moldable and hasgood stability and wear characteristics such as for instance, Delrinacetal resin, nylon or Bakelite. Notches 42 in the sidewalls 38 are ofsufficient size to accommodate the lower middle roll 28 while notchesnotches 44 in the sidewalls 38 are larger than the supporting shaft 45of the upper roll 18 for reasons hereinafter explained. Lower apronclearing member 31 is hollow and telescopes over hollow projections (notshown) molded to sidewalls 38 and is secured in such position by fingerswhich are integral with bar member 52 and engage the outsides of rovingbar receptacles 54 to urge Walls 38 toward one another. A notch 56 isprovided in each of the cradle sidewalls 38 to allow circular tabprojections 58 on the upper apron clearing member 30 to slide therein toposition member 30. Tabs 58 in conjunction with apron 26 positions themember 30 in operative position against the upper drafting roll 18.

FIG. 4 shows in detail the roving stop 60 which, as shown in FIGS. 1-3,extends across two drafting positions and encircles a portion of thediameters of lower back rolls 16. The roving stop 60, like the cradle32, is made from a readily moldable material which has good stabilityand wear characteristics. The roving stop 60 is circular in shape andhas a diameter slightly less than the diameter of rolls 16. The edge ofthe rev ing stop 60 adjacent to the incoming roving is thinner than theopposite edge to provide for ease of movement into the nip of rolls 14and 16. Also the edges 62 are higher than the edges 64 to allow only asmall portion of the stop 60'to enter the nip of rolls l4 and 16initially. Molded to the bottom of the roving stop 60 is an elongatedroving stop portion 66, which can have a serrated edge, if desired, andfunctions upon the occurrence of an ends down to bite into the roving 10as hereinafter described. Also, preferably molded to the roving to thestop 60 are tabs 68 which are engaged by hook members 70 to prevent theroving stop 60 from rotating with the rolls 16 in normal operation. Afurther tab member 72 is provided to engage the trumpet support 13 whenthe roving stop 60 is actuated to limit the rotational movement of theroving stop 60. A truncated projection 74 is also provided to aid anoperation in resetting the roving stop 60 after it has been actuated.

Mounted on the roll shaft on boss 46 of the lower middle rolls, betweentwo adjacent drafting positions is the roving stop actuation mechanism,generally designated 76. Basically, the mechanism consists of elongatedside members 78 and 80 which span the three roll positions and have anotch 82 therein which engages the shaft or boss 46. The wall membersare secured together by cross-connecting bars 84. Preferably, themechanism 76 will be molded from a readily moldable material which hasgoodrstability and wear characteristics and in which case the crossbars84 will be integral with the wall mem-' bers.

Looking now in more detail at FIG. 1 and 2, the drafting system is shownin the operative and inoperative positions, respectively. In FIG. 1, themechanism 76 is so positioned that the hook portion 70 at one endengages the tab 68 to prevent the rotation of the roving stop 60 withthe roll 16 and the finger portion 86 at the other end is riding on theboss 88 between the upper front drafting rolls 22.

Looking now to FIG. 2, the action of the cradle assembly is illustratedwhen the yarn end 90 breaks. Since the yarn end between the nip of thefront rolls 22 and 24 is broken and roving is still being supplied, theroving will tend to lap around the bottom roll and build up in the areabetween the nip of the front rolls and the nose portions of the apron.As the lap 92 increases in diameter it will contact the apron 28 causingthe cradle to rotate clockwise around the rolls 18 and 20. This isaccomplished since the notches 56 in the cradle sidewalls allow the tabs58 to move forward as the cradle rotates and the upper roll 18 does notrestrict such movement.

At the same time the roll 22 will move upwardly thereby moving thefinger portion 86 in the clockwise direction causing the roving stopactuation mechanism 76 to pivot in a clockwise direction around theshaft or boss 46 of the middle lower roll 20. When the lap 92 has builtup to a certain point, the roving stop actuation mechanism 76 will haverotated to a point when the hook portion 70 thereof is disengaged fromthe tabs 68 on the roving stop 60 thereby allowing the roving stop 60 torotate with the lower rear roll 16 until the triangularshaped rovingstop portion 66 bites into the roving l and prevents further delivery ofthe roving into the nip of rolls l4 and 16 thereby preventing furtherbuildup of the lap 92.

A bottom roll lap has been described above but essentially the sameaction will occur if the lap builds up on the top roll except that thecradle will not be rotated. It is obvious that the buildup of a lap onthe top roll 22 will push the finger portion 86 upwardly to pivot theroving stop actuation mechanism and release the roving stop 60.

As discussed previously, the roving stop member has a tab 72 thereonwhich contacts the trumpet support 13. This tab 72 basically is toprevent the further rotation of the roving stop 60 when the top rollsl4, l8 and 22 have been lifted in order to remove the lap and place thedrafting system back in operation.

The herein improved system provides a drafting apparatus which will notnormally be damaged if a lap builds up on either of the front draftingrolls. Further, such apparatus will automatically cut off the supply ofroving to the drafting upon the occurrence of the formation of a lap oneither of the front drafting rolls.

Although we have described in detail the preferred embodiment of theinvention, we contemplate that many changes may be made withoutdeparting from the scope or spirit of the invention and we desire to belimited only by the claims.

That which is claimed is:

l. A drafting system comprising: at least three pairs of drafting rollsspaced from one another in operative relationship, each of said pairs ofdrafting rolls being in nip forming relationship, an arcuate-shapedfiber stop means partially encircling one roll of one pair of rolls,said fiber stop means having a portion thereof adapted to rotate intothe nip of the roll on which it partially encircles and means mounted onone roll of a second pair of rolls of said three pairs of rolls andincluding a first portion operably associated with the top roll of athird pair'of rolls for sensing the upward movement thereof and a secondportion engaging said fiber stop means to prevent said fiber stop meansfrom rotating with the roll on which it is mounted and to release andallow said fiber stop means to rotate with the roll on which it ismounted to place said portion in the nip of said one pair of rolls uponsensing the upward movement of said top roll of said third pair of rollsdue to a lap on either roll of said third pair of rolls.

2. The structure of claim 1 wherein said second portion of said meansincludes a hook portion engaging said stop means during normal operationof said drafting system.

3. The structure of claim 2 wherein said stop means is mounted on thebottom roll of said first pair of rolls.

4. The structure of claim 3 wherein said means is pivotally mounted onthe bottom roll of said second pair of rolls.

5. The drafting system of claim 1 wherein a second set of three pairs ofrolls is provided spaced from the first set of three pairs of rolls andsaid means mounted on one roll of a second pair of rolls is locatedbetween the two sets of rolls.

1. A drafting system comprising: at least three pairs of drafting rollsspaced from one another in operative relationship, each of said pairs ofdrafting rolls being in nip forming relationship, an arcuate-shapedfiber stop means partially encircling one roll of one pair of rolls,said fiber stop means having a portion thereof adapted to rotate intothe nip of the roll on which it partially encircles and means mounted onone roll of a second pair of rolls of said three pairs of rolls andincluding a first portion operably associated with the top roll of athird pair of rolls for sensing the upward movement thereof and a secondportion engaging said fiber stop means to prevent said fiber stop meansfrom rotating with the roll on which it is mounted and to release andallow said fiber stop means to rotate with the roll on which it ismounted to place said portion in the nip of said one pair of rolls uponsensing the upward movement of said top roll of said third pair of rollsdue to a lap on either roll of said third pair of rolls.
 2. Thestructure of claim 1 wherein said second portion of said means includesa hook portion engaging said stop means during normal operation of saiddrafting system.
 3. The structure of claim 2 wherein said stop means ismounted on the bottom roll of said first pair of rolls.
 4. The structureof claim 3 wherein said means is pivotally mounted on the bottom roll ofsaid second pair of rolls.
 5. The drafting system of claim 1 wherein asecond set of three pairs of rolls is provided spaced from the first setof three pairs of rolls and said means mounted on one roll of a secondpair of rolls is located between the two sets of rolls.